Ruger .450 Bushmaster 9-Round Magazine

.450 Bushmaster is a big-bore straight-wall cartridge that launches a 250-grain bullet at .45-70 class energy levels from an AR-15 magazine well. The cartridge geometry is dramatically different from 5.56, and dedicated single-stack magazines are required. Ruger's factory .450 Bushmaster magazine ships with the AR-556 MPR rifle and is the most widely available option.

The 9-round capacity is set by the cartridge's case head diameter and overall length. The polymer body uses an internal geometry tuned for the wide .452-caliber projectile and the short, fat straight-wall case. Single-stack feeding is more positive than double-stack alternatives at this case diameter, which matters for hunting reliability where second shots count.

For hog and deer hunters in straight-wall states using a .450 Bushmaster AR-15, two or three of these magazines is the right loadout. The cartridge is too punishing to shoot in volume, and a single 9-round mag handles most field stalking. Hexmag and X Products make alternatives at higher capacities but with less consistent reliability records.